(a) Field of the Invention
This invention relates broadly to the cooling and heating of the inside of a highway transport trailer and more particularly, but not by way of limitation, to an airflow system and method for maintaining a constant temperature inside both a lead or front trailer and inside an attached xe2x80x9cpupxe2x80x9d or rear trailer. The airflow system using a single refrigeration unit mounted on the front of the lead trailer.
(b) Discussion of Prior Art
Heretofore, there have been a variety of different types of cooling systems and refrigeration units used with highway transport trucks and trailers and railroad cars when transporting perishable fruits, vegetables and other items. In U.S. Pat. No. 2,303,867 to Stebbins, an early method of refrigerating railroad cars and commercial trucks is disclosed. A cooling unit is attached to a side of a railroad car or a truck and cold air is circulated around and past perishable vegetables. In U.S. Pat. No. 2,937,510 to Allyne, an apparatus for controlling temperature inside a trailer is described. The trailer includes a refrigeration unit adapted to contain Dry Ice. Using a fan, air is drawn upwardly from a cargo space and through an air-cooling space and back over the top of the cargo. In U.S. Pat. No. 4,934,255 to McDonnell et al., a food treating apparatus and method for ripening fruit without having to remove the fruit from a truck or trailer is illustrated. A fruit ripening unit with air circulating system is parked next to a rear of three trucks for circulating air at a controlled temperature into the trucks with stored fruit. In U.S. Pat. No. 3,972,674 to Harrell, a crop drying apparatus is disclosed for drying tobacco, peanuts and grain hung inside a trailer.
None of the above mentioned prior art patents specifically disclose the unique features, structure and function of the subject airflow system used with a lead trailer with a refrigeration unit and attached pup trailer for maintaining a constant temperature inside both of the trailers and using the same refrigeration unit.
In view of the foregoing, it is a primary objective of the subject airflow system to provide a constant temperature to goods and products being transported inside a lead trailer with refrigeration unit and inside a pup trailer and using only a single refrigeration unit for cooling or heating the two trailers. For example, during the transporting of beer, the airflow system maintains the temperature of the stored beer at 40 degrees F. in both front and rear trailers. Also, depending on the heating and cooling capacity of the refrigeration unit, the two trailers can be heated and cooled at a constant temperature in a range of 35 to 60 degrees F. The two trailers are used for carrying various types of goods and products that require a constant temperature when being transported.
Another object of the invention is the subject airflow system can be used with both a standard 48 foot or 53 foot lead trailer with refrigeration unit and with an attached 28 foot or 32 foot pup trailer. The combination of the lead and pup trailers provide for increased payloads of the goods being shipped, less transportation cost and less maintenance cost.
Still another object of the airflow system is it can be quickly disconnected from the lead and pup trailers so that each trailer can be used independently of each other when the new airflow system is not required.
Yet another object of the invention is the airflow system can be retrofitted for different lengths of lead trailers and pup trailers, when the overall length of the two units is approved by state and federal law.
The airflow system is adapted for attaching to a refrigeration unit mounted on a front of a lead trailer and adapted for attaching to a pup trailer pulled behind the lead trailer. The airflow system uses the heated or cooled airflow discharged from the refrigeration unit to either heat or cool goods at a constant temperature. The goods are stored inside the lead trailer and the pup trailer. The airflow system conveys the airflow along the length and the top of both the lead trailer and the pup trailer. The airflow is then redirected back along the length and the bottom of both the pup trailer and the lead trailer heating and cooling the goods at a constant temperature. The return airflow is then drawn into the refrigeration unit and recirculated.
The airflow system includes a modified air chute having a first end adapted for attaching to an air discharge opening in the refrigeration unit. A second end of the air chute is attached to a rear door air manifold. The air manifold is mounted on an upper portion of one of the lead trailer""s rear doors. The rear door manifold is disposed around a lead airflow transfer hole in the rear door. The transfer hole is connected to one end of a transfer tube. An opposite end of the transfer tube in connected to a pup airflow intake hole. The intake hole is in an upper portion of the front of the pup trailer.
The airflow, received from the lead trailer, is circulated along the length and the top of the pup trailer where it engages the pup""s rear door. The airflow is then redirected back along the bottom and floor of the pup trailer before returning through a pup airflow return hole. The return hole is in a lower portion of the front of the pup trailer. The return hole is connected on one end of a return tube. An opposite end of the return tube is connected to a lead airflow return hole. The lead airflow return hole is in a lower portion of the lead trailer""s rear door. The airflow is discharged along the bottom and floor of the lead trailer before being received in an air return opening in the refrigeration unit.
These and other objects of the present invention will become apparent to those familiar with various types of refrigeration units used for heating and cooling products transported by trailers when reviewing the following detailed description, showing novel construction, structure, function and method steps as described herein, and more particularly defined by the claims, it being understood that changes in the various embodiments to the invention are meant to be included as coming within the scope of the claims, except insofar as they may be precluded by the prior art.